Multi-Focal Laser Direct Writing through Spatial Light Modulation Guided by Scalable Vector Graphics

Author(s):

Duan, Linhan; Zhu, Yueqiang; Bai, Haoxin; Zhang, Chen; Wang, Kaige; Bai, Jintao & Zhao, Wei

Abstract:

“Multi-focal laser direct writing (LDW) based on phase-only spatial light modulation (SLM) can realize flexible and parallel nanofabrication with high-throughput potential. In this investigation, a novel approach of combining two-photon absorption, SLM, and vector path-guided by scalable vector graphics (SVGs), termed SVG-guided SLM LDW, was developed and preliminarily tested for fast, flexible, and parallel nanofabrication. Three laser focuses were independently controlled with different paths, which were optimized according to the SVG to improve fabrication and promote time efficiency. The minimum structure width could be as low as 81 nm. Accompanied by a translation stage, a carp structure of 18.10 μm × 24.56 μm was fabricated. This method shows the possibility of developing LDW techniques toward fully electrical systems, and provides a potential way to efficiently engrave complex structures on nanoscales.”

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Publication: Micromachines
Issue/Year: Micromachines, Volume 14; Number 4; Pages 824; 2023
DOI: 10.3390/mi14040824

Extending the Imaging Depth of Field through Scattering Media by Wavefront Shaping of Non-Diffraction Beams

Author(s):

Han, Tongyu; Peng, Tong; Li, Runze; Wang, Kaige; Sun, Dan & Yao, Baoli

Abstract:

“Increasing the depth of field (DOF) is a crucial issue for imaging through scattering media. In this paper, an improved genetic algorithm is used to modulate the wavefront of light through scattering media, by which high-quality refocusing and imaging through scattering media are achieved. Then, the DOF of the imaging system is effectively extended by further modulating the refocused beam into a non-diffraction beam. Two kinds of non-diffraction beams, i.e., a Bessel beam and Airy beam, were produced as a demonstration. The experimental results show that compared to the Gaussian beam, the DOF of the imaging system by combining the wavefront shaping and non-diffraction Bessel beam or Airy beam can be improved by a factor of 1.1 or 1.5, respectively. The proposed method is helpful for the technical development of high-quality imaging through scattering media with a large DOF.”

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Publication: Photonics
Issue/Year: Photonics, Volume 10; Number 5; Pages 497; 2023
DOI: 10.3390/photonics10050497

Controllable nonlinear propagation of partially incoherent Airy beams

Author(s):

Chen, Kaijian; Zhang, Peiyu; Liu, Nana; Tan, Liu; Hong, Peilong; Zou, Bingsuo; Xu, Jingjun & Liang, Yi

Abstract:

“The self-accelerating beams such as the Airy beam show great potentials in many applications including optical manipulation, imaging and communication. However, their superior features during linear propagation could be easily corrupted by optical nonlinearity or spatial incoherence individually. Here we investigate how the interaction of spatial incoherence and nonlinear propagation affect the beam quality of Airy beam, and find that the two destroying factors can in fact balance each other. Our results show that the influence of coherence and nonlinearity on the propagation of PIABs can be formulated as two exponential functions that have factors of opposite signs. With appropriate spatial coherence length, the PIABs not only resist the corruption of beam profile caused by self-focusing nonlinearity, but also exhibits less anomalous diffraction caused by the self-defocusing nonlinearity. Our work provides deep insight into how to maintain the beam quality of self-accelerating Airy beams by exploiting the interaction between partially incoherence and optical nonlinearity. Our results may bring about new possibilities for optimizing partially incoherent structured field and developing related applications such as optical communication, incoherent imaging and optical manipulations.”

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Publication: arXiv
Issue/Year: arXiv, 2023
DOI: 10.48550/ARXIV.2304.02326

Multi-Bessel Beams Generated by an Axicon and a Spatial Light Modulator for Drilling Applications

Author(s):

Lutz, Christian; Schwarz, Simon; Marx, Jan; Esen, Cemal & Hellmann, Ralf

Abstract:

“We report on an optical setup to generate multi-Bessel beam profiles combining a refractive axicon and a spatial light modulator. Based on their particular beam profile, Bessel beams offer advantageous properties for micro drilling processes and internal volume processing, especially for transparent materials. In addition, the laser power of industrial, ultrashort pulsed lasers has increased significantly over the last few years, offering the possibility for highly efficient processes
using multi-spot profiles. Our optical concept combines the dynamic possibilities of beam splitting using a spatial light modulator with the benefits of Bessel beams, which facilitates multi-Bessel beam processing. Beside the simulation and experimental evaluation of the generated multi-Bessel beams, we exemplify the applicability of the developed module for the perforation of thin metal foils by micro drilling.”

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Publication: Photonics
Issue/Year: Photonics, Volume 10; Number 4; Pages 413; 2023
DOI: 10.3390/photonics10040413

Improving longitudinal resolution of Airy beams two-photon volume imaging with fluorescence lifetime imaging

Author(s):

Guo, Yong; Wang, Luwei; Zhu, Yinru; Gao, Xinwei; Weng, Xiaoyu; Liu, Jinyuan; Yan, Wei & Qu, Junle

Abstract:

“The non-diffracting Airy beams have been reported to increase acquisition speed by projecting the axially significantly elongated information to a two-dimensional (2D) image. Due to the elongated focal length, an Airy volumetric image can cover information as much as stack images with multiple Gaussian images at different imaging depths, which significantly increases the volumetric imaging rate. However, the projection of three-dimensional (3D) structures on a 2D plane is usually indistinguishable, especially those that overlap along the axis. Therefore, we proposed an axially resolved volume imaging technique based on a two-photon fluorescence lifetime microscopy imaging (FLIM) by using Airy beams.”

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Publication: Optics Communications
Issue/Year: Optics Communications, Volume 530; Pages 129151; 2023
DOI: 10.1016/j.optcom.2022.129151

Airy transform of Laguerre-Gaussian beams

Author(s):

Zhou, Guoquan; Wang, Fei & Feng, Shangshen

Abstract:

“Airy transform of Laguerre-Gaussian (LG) beams is investigated. As typical examples, the analytic expressions for the Airy transform of LG01, LG02, LG11, and LG12 modes are derived, which are special optical beams including the Airy and Airyprime functions. Based on these analytical expressions, the Airy transform of LG01, LG02, LG11, and LG12 modes are numerically and experimentally investigated, respectively. The effects of the control parameters and on the normalized intensity distribution of a Laguerre-Gaussian beam passing through Airy transform optical systems are investigated, respectively. It is found that the signs of the control parameters only affect the location of the beam spot, while the sizes of the control parameters will affect the characteristics of the beam spot. When the absolute values of the control parameters and decrease, the number of the side lobes in the beam spot, the beam spot size, and the Airy feature decrease, while the Laguerre-Gaussian characteristic is strengthened. By altering the control parameters and , the performance of these special optical beams is diversified. The experimental results are consistent with the theoretical simulations. The Airy transform of other Laguerre-Gaussian beams can be investigated in the same way. The properties of the Airy transform of Laguerre-Gaussian beams are well demonstrated. This research provides another approach to obtain special optical beams and expands the application of Laguerre-Gaussian beams.”

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Publication: Optics Express
Issue/Year: Optics Express, Volume 28; Number 13; Pages 19683; 2020
DOI: 10.1364/oe.395982